The invention relates to a bone joining plate for securing the bone pieces of a bone fracture.
Joining plates are already used in case of fracture of the bones, e.g. the ankle or the wrist.
The purpose of such osteosynthesis with plate is the stable immobilization of the broken bone-ends in the proper position. This can only be achieved if the plate securing screws are fixed in the bone in sufficient quantity and in adequate quality. In case of fractures of the limbs generally sufficient room is available at both fractured ends for putting on the plate, the cortex ensures the safe anchorage of the screws. However in case of near-joint fractures, or those penetrating the joint, the bony substance is spongy, the cortex is thin and soft, the fractured end near the surface of the joint is frequently fragmentary and small. Thus in this case securing of the plate with screws is hardly possible: their anchorage in the soft and small pieces is inadequate. Under such conditions not even an adaptation synthesis can successfully be performed.
Similar problems appear in case of--mainly old--patients, whose bone structure is loose and more atrophied than the average. The metal screws do not become properly fixed in the thin, spongy bone, consequently the metal plate can not be satisfactorily secured with the screws, especially when in case of fragmentary fracture some of the line of breaks are at the spot of one or another screw. Such screws have no fixing effect.
The object of the present invention is a bone joining plate which is suitable for securing the fractured bones even when the screwing alone is insufficient and which is easily adaptable to the conditions of application before or during the operation.
According to the invention, a bone joining plate is provided having an oblong plate curved according to the bone surface, where at least two holes are arranged along the longitudinal axis and at least three pointed claws bent from the material of the plate are arranged at one of its ends. One of the claws is arranged suitably in the direction of the longitudinal axis of the plate and at least one further claw is perpendicularly arranged on each side of the plate.
The holes may be circular or oval shaped, the latter one allows the excentric arrangement of screws, whereby compression may be applied to the fractured surfaces.
The bone joining plate according to the invention can be produced with claws laying in the plane, or tangent-plane of the plate, but the claws may also be bent from the plane of the plate, which makes their further shaping unnecessary.
By securing of the plate the claws formed at one end can be bent to any optional plane with the use of pliers, and by hammering them into the bony substance, the anchorage of the plate-end is maximally ensured. The screws driven through the holes between the claws protect against slip-out. The superfluous claws which are not needed for anchorage are removed with nippers. The other holes of the plate can be used partly or fully for anchorage on the other fractured end. The plates can be produced in different lengths and with different number of holes for handling the various fractures. They are well applicable for example for the following:
securing the near-joint or joint fracture at the distant end of the radius; PA1 securing the fragmentary near-joint or joint fracture at the near-end of the ulna; PA1 securing the fractures of the outer ankle/the profile of this alternative is bent in advance conforming to the anatomical shape of the ankle appendix/; PA1 securing the near-joint fracture or the one penetrating the joint at the distant end of the tibia; PA1 securing the fragmentary, near-joint or joint fractures of the upper arm bone, or PA1 securing the femur and the tibia during the axial readjustment near the knee.
Further details of the invention are described by way of examples with the aid of drawings, in which: